1. Field of the Invention
The present invention generally relates to bi-directional communication links comprised of a high bandwidth link and a low bandwidth link and, more particularly, to such communications links in which the direction of the high bandwidth link is dynamically reversed in response to data traffic conditions to create virtual high bandwidth data channels in both directions.
2. Background Description
There are several systems with a bi-directional communication link where the bandwidth in one direction must always be far greater than the bandwidth in the other direction. Such systems, however, cannot handle wide variations in data traffic flowing in the low bandwidth direction.
In database systems that do database queries and information retrieval, a user sends a query to some information server and receives a response. The query message comprises a small amount of bytes, but the response could be a very large data stream comprising graphics, images and text. These systems require a high bandwidth link downstream to the user and a low bandwidth link upstream to the server. However, users often have large databases on their local machine that need to be transferred to another location. For example, a local business office may execute many transactions during the day on a local database and then require that the database be backed up to a remote site. During the day, transactions information are received from some central server on the high bandwidth link. At the end of the day, the high bandwidth link is required in the reverse direction to provide speedy backup.
Browsing the World Wide Web on the Internet is another application that requires links with different bandwidths in each direction. When a user is browsing another site, the high bandwidth link is required in the downstream direction. However, the user may have a set of web pages on the local machine that are being read by a remote site. In this case, the high bandwidth link is needed in the upstream direction.